The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform

Xiaoyun Zhang - One of the best experts on this subject based on the ideXlab platform.

  • generalized scaling of spontaneous imbibition data for strongly water wet systems
    Journal of Petroleum Science and Engineering, 1997
    Co-Authors: Ma Shouxiang, Norman Robert Morrow, Xiaoyun Zhang
    Abstract:

    Mass transfer between fractures and matrix blocks is critical to oil recovery by waterflooding in fractured reservoirs. A scaling equation has been used for rate of oil recovery by spontaneous imbibition and presented their results as oil recovery vs. Dimensionless Time. Many conditions apply to this scaling equation, including identical core sample shapes and fluid viscosity ratios. Recent investigation by experiment of these two factors has resulted in a more generalized scaling equation for strongly water-wet systems with a general definition of characteristic length and a viscosity ratio term included in the definition of Dimensionless Time. In this paper, published data on oil recovery by imbibition have been analyzed and correlated through application of the new definition. These data sets were for different porous media, core dimensions, boundary conditions, and oil and water viscosities. All of the systems were strongly water-wet. The generalized correlation was fitted closely by an empirical mass transfer function with the new definition of Dimensionless Time as the only parameter.

  • Generalized Scaling Of Spontaneous Imbibition Data For Strongly Water-Wet Systems
    Technical Meeting Petroleum Conference of The South Saskatchewan Section, 1995
    Co-Authors: Norman Robert Morrow, Xiaoyun Zhang
    Abstract:

    Mass transfer between fractures and matrix blocks is critical to oil recovery by waterflooding in fractured reservoirs. A scaling equation has been used for rate of oil recovery by spontaneous imbibition and presented their results as oil recovery vs. Dimensionless Time. Many conditions apply to this scaling equation, including identical core sample shapes and fluid viscosity ratios. Recent investigation by experiment of these two factors has resulted in a more generalized scaling equation for strongly water-wet systems with a general definition of characteristic length and a viscosity ratio term included in the definition of Dimensionless Time. In this paper, published data on oil recovery by imbibition have been analyzed and correlated through application of the new definition. These data sets were for different porous media, core dimensions, boundary conditions, and oil and water viscosities. All of the systems were strongly water-wet. The generalized correlation was fitted closely by an empirical mass transfer function with the new definition of Dimensionless Time as the only parameter. © 1997 Elsevier Science B.V.

Mikhail A. Sheremet - One of the best experts on this subject based on the ideXlab platform.

  • Combined natural convection heat and mass transfer in an enclosure having finite thickness walls
    Meccanica, 2013
    Co-Authors: Mikhail A. Sheremet
    Abstract:

    Unsteady three-dimensional conjugate heat and mass transfer in an enclosure having finite thickness heat-conducting walls has been analyzed numerically. The governing unsteady, three-dimensional flow, energy and contaminant transport equations for the gas cavity and unsteady heat conduction equation for solid walls, written in Dimensionless terms of the vector potential functions, the vorticity vector, the temperature and the concentration, have been solved using an iterative implicit finite-difference method. Main attention was paid to the effects of the Rayleigh number, buoyancy ratio and the Dimensionless Time on the flow structure and heat and mass transfer regimes. It should be noted that the dominant cause of the oscillations in the Dimensionless Time dependences of the average Nusselt number on the heat source surface and the average Sherwood number on the contaminant source surface at Ra>5⋅10^5 is the mutual influence of the analyzed object geometry and the thermo-diffusivity impact on the flow. The change in the buoyancy ratio can lead to the essential modifications of the flow, temperature and concentration fields owing to the significant influence of the concentration gradient.

  • Numerical Analysis of Convective Heat Transfer in a Closed Two-Phase Thermosyphon
    Journal of Engineering Thermophysics, 2011
    Co-Authors: G. V. Kuznetsov, M. A. Al-ani, Mikhail A. Sheremet
    Abstract:

    Mathematical modeling of the processes of heat transfer and hydrodynamics in a closed two-phase thermosyphon is carried out in a wide range of key parameters. The mathematical model is based on the laws of conservation of mass, momentum, and energy in Dimensionless variables of stream function-vorticity vector-temperature. The influence of the Rayleigh number and the Dimensionless Time on the local and integral thermal hydrodynamic characteristics is estimated.

Norman Robert Morrow - One of the best experts on this subject based on the ideXlab platform.

  • generalized scaling of spontaneous imbibition data for strongly water wet systems
    Journal of Petroleum Science and Engineering, 1997
    Co-Authors: Ma Shouxiang, Norman Robert Morrow, Xiaoyun Zhang
    Abstract:

    Mass transfer between fractures and matrix blocks is critical to oil recovery by waterflooding in fractured reservoirs. A scaling equation has been used for rate of oil recovery by spontaneous imbibition and presented their results as oil recovery vs. Dimensionless Time. Many conditions apply to this scaling equation, including identical core sample shapes and fluid viscosity ratios. Recent investigation by experiment of these two factors has resulted in a more generalized scaling equation for strongly water-wet systems with a general definition of characteristic length and a viscosity ratio term included in the definition of Dimensionless Time. In this paper, published data on oil recovery by imbibition have been analyzed and correlated through application of the new definition. These data sets were for different porous media, core dimensions, boundary conditions, and oil and water viscosities. All of the systems were strongly water-wet. The generalized correlation was fitted closely by an empirical mass transfer function with the new definition of Dimensionless Time as the only parameter.

  • Generalized Scaling Of Spontaneous Imbibition Data For Strongly Water-Wet Systems
    Technical Meeting Petroleum Conference of The South Saskatchewan Section, 1995
    Co-Authors: Norman Robert Morrow, Xiaoyun Zhang
    Abstract:

    Mass transfer between fractures and matrix blocks is critical to oil recovery by waterflooding in fractured reservoirs. A scaling equation has been used for rate of oil recovery by spontaneous imbibition and presented their results as oil recovery vs. Dimensionless Time. Many conditions apply to this scaling equation, including identical core sample shapes and fluid viscosity ratios. Recent investigation by experiment of these two factors has resulted in a more generalized scaling equation for strongly water-wet systems with a general definition of characteristic length and a viscosity ratio term included in the definition of Dimensionless Time. In this paper, published data on oil recovery by imbibition have been analyzed and correlated through application of the new definition. These data sets were for different porous media, core dimensions, boundary conditions, and oil and water viscosities. All of the systems were strongly water-wet. The generalized correlation was fitted closely by an empirical mass transfer function with the new definition of Dimensionless Time as the only parameter. © 1997 Elsevier Science B.V.

Dale R Durran - One of the best experts on this subject based on the ideXlab platform.

  • vortex formation and vortex shedding in continuously stratified flows past isolated topography
    Journal of the Atmospheric Sciences, 1997
    Co-Authors: Christoph Schar, Dale R Durran
    Abstract:

    Abstract The flow of a nonrotating atmosphere with uniform stratification and wind speed past an isolated three-dimensional topographic obstacle is investigated with a nonhydrostatic numerical model having a free-slip lower boundary. When the mountain is sufficiently high, the transient development of a quasi-steady flow occurs in two phases. During the first phase, which occurs over a Dimensionless Time of O(1), the flow is essentially inviscid and adiabatic, and potential vorticity (PV) is conserved. The transient evolution of the flow during the second phase, which occurs over a Dimensionless Time of O(10) to O(100), is controlled by dissipation and is accompanied by the generation of PV anomalies. Two cases are examined in which the flow is forced to remain left–right symmetric with respect to the axis of the incident flow. In the first, the Dimensionless mountain height NH/U is 1.5, and gravity waves break over the mountain. In the second, NH/U = 3, and a quasi-steady recirculating wake containing a ...

A. V. Butkovskii - One of the best experts on this subject based on the ideXlab platform.

  • Reynolds analogy for the Rayleigh problem at various flow modes.
    Physical Review E, 2016
    Co-Authors: A. A. Abramov, A. V. Butkovskii
    Abstract:

    The Reynolds analogy and the extended Reynolds analogy for the Rayleigh problem are considered. For a viscous incompressible fluid we derive the Reynolds analogy as a function of the Prandtl number and the Eckert number. We show that for any positive Eckert number, the Reynolds analogy as a function of the Prandtl number has a maximum. For a monatomic gas in the transitional flow regime, using the direct simulation Monte Carlo method, we investigate the extended Reynolds analogy, i.e., the relation between the shear stress and the energy flux transferred to the boundary surface, at different velocities and temperatures. We find that the extended Reynolds analogy for a rarefied monatomic gas flow with the temperature of the undisturbed gas equal to the surface temperature depends weakly on Time and is close to 0.5. We show that at any fixed Dimensionless Time the extended Reynolds analogy depends on the plate velocity and temperature and undisturbed gas temperature mainly via the Eckert number. For Eckert numbers of the order of unity or less we generalize an extended Reynolds analogy. The generalized Reynolds analogy depends mainly only on Dimensionless Time for all considered Eckert numbers of the order of unity or less.